Striking systems of the type including a plurality of striking devices arranged side by side are well known. Each such striking device is formed by a flat electromagnetic coil integral with a striking hammer, arranged in a case and subjected to the action of magnetic fields perpendicular to the plane of said coil, the case being mounted on a support by means of a deformable elastic suspension unit. Thus, when a current is caused to circulate in one of said coils, the latter is subjected to the action of an electromagnetic force which displaces the corresponding device in the direction of the paper with the purpose of effecting a striking operation, this displacement entailing the elastic deformation of the suspension unit. Upon disappearance of this current, the electromagnetic force ceases and the striking device is restored to its initial position owing to the restoring energy that is communicated to it at the instant of its impact on the striking anvil.
Such a striking system is efficacious, but because of the large size of each of its devices, it can be used only for striking symbols or characters all at once and not for forming them in the form of a plurality of separately formed dots.
Striking devices designed for dot printers are also known in the art. These devices comprise a plurality of pins activated by a complex system of rods. Their operation and maintenance are delicate and complicated and their implementation is far from satisfactory.